I have read about research evidence that biphasic sleep (i.e. sleeping 2 times every 24 hours instead of once) is probably closer to the normal human rhythm.

Typically two approaches are mentioned:

A 1-sleep cycle nap late in the afternoon or early in the evening followed by a 3 or 4-sleep cycle core sleep which will end around 7AM in the morning

Two 2 or 3-sleep cycle periods with 1 or 2 hours in between

Given that the latter will fit more easily to my current schedule (with 5 sleep-cycles of monophasic sleep) I am interested to try that.

My main question is: how do I switch from my current rhythm to the biphasic sleep rhythm? Do I have to set an alarm in the middle of the night? I guess so in the beginning, but do I have to keep doing that or will I at some point wake up by myself? Or is there a different way of getting to the biphasic rhythm?

A side question is: I know that sleep cycles are about 75-90 minutes, but how do I figure out how much it is. Especially if I'm going to start doing only 2 after each other I can imagine that it matters quite a bit whether I adjust to 75 or to 90 min.

5 Answers
5

I've been doing polyphasic sleeping for almost one year (Everyman with two naps, but I am thinking about switching to biphasic sleeping since it seems more natural).

Here is what you could do (supposing you want to try the "standard" biphasic with 6-hours core sleep and one 20-minutes day nap):

Know your the length of your own sleep cycle.

1.1 Take a paper sheet and draw a circle representing a 24-hours day. Decide your go-to-bed time and draw the 6-hours core sleep slice from there. Then draw the 20-minutes slice in the middle of your day and calculate the nap's starting time. This will be your initial schedulle. Just stick to it!

1.2 Do it and log. Sleep according to your schedule. Sometimes you won't be able to stick to it, so log everything into a file: your go-to-bed and go-to-nap times, the length of your nights and naps, how you feel, each time you oversleep. And above all: try to log when you naturally wake up during the night. This will give you very important information on your own cycles.

1.3 Calculate and adjust. When you have enough data in your log file, analyse them. Correlate the actual length of your nights with your next day feelings, etc. Typically, you want to find a night where you naturally woke up. Then just calculate (waking up time - go-to-bed time). Do that a few times and it will give you the average length of your own cycle.

Adjust your schedule. Once you know the length of your cycle, re-calculate the size of your core sleep slice: (own length)*4. It may be 10 minutes longer or 10 minutes shorter. Stick to that. --Don't change the length of your naps.

Repeat this process a few times, until you feel good. It may take several weeks or even months (it took me about 3 months).

Try to stick very closely to your schedule, especially at the beginning. But I can tell you even if you do it seriously, you will feel like a zombi during at leat one week...

I've just launched a new website to cover this subject: http://www.biphasicsleep.com (it's quite fresh, but I put content on a regular basis...)

When it comes to Polyphasic sleep I know of no better reference than my favorite alternative lifestyle guy, Steve Pavlina. He tried a VERY extensive polyphasic sleep experiment a few years back and I am still itching to try it due to the success he had but life around me is not working that way.

I have recently started using a polyphasic sleep schedule (6 hour core sleep with a 20 min nap). To do this, I basically just started taking a nap in the middle of the day when I was able and then going to bed later. After a few days of this, I found that I wanted to go to bed for my core sleep earlier rather than later and so I allowed myself to do that, but set an alarm to wake myself up after six hours of sleep. The final schedule that I settled into was core sleep from about 11pm to 5am with a 20-30 min nap between 11am and 1pm.

As for figuring out whether you're getting enough sleep cycles, just try adjusting your core sleep by 15-20 minutes and see whether you feel noticeably more tired. Also, if your alarm wakes you from a dream, you're in the middle of a cycle.

This looks pretty good - but is it possible to get some references as well?
–
JoeAug 31 '13 at 22:11

Well, I can't provide references to my experiences, but you can try the Polyphasic Society for a lot more information about different schedules and how to transition to them.
–
William EverettSep 2 '13 at 17:02

I meant the ' if your alarm wakes you from a dream, you're in the middle of a cycle.' part. :)
–
JoeSep 2 '13 at 20:34

This is part of the definition of a sleep cycle. There are several cycles that you go through each night including a few different kinds of non-REM sleep and REM (dreaming) sleep. If you're dreaming, then you're experiencing REM sleep which is one of the cycles that you go through a few times per night. Wikipedia's article on sleep is pretty good at describing the different stages and how they're measured. It's important to note that just because you're not dreaming doesn't mean you're at the end of a sleep cycle. REM sleep is only one type of cycle.
–
William EverettSep 3 '13 at 19:30

I did this for quite a while last year and what I found that an alarm was almost always needed....otherwise I worried about oversleeping while I slept, which made it less deep.

I forget the brand (and am not at home) but it was a huge help to get an alarm that gradually lights up my room and plays natural sounds as it does so. Such a better way to wake up then an abrupt alarm clock.